1. Field of the Invention
The present invention relates to an examination device, an examination method, and a computer program product.
2. Description of the Related Art
In high quality printing such as production printing, quality examinations of printed matters are required. For example, there are known examination devices that detect defects present in printed matters based on read images generated by electrically reading the printed matters, to examine the quality of the printed matters based on the detected defects.
As defects present in printed matters, there are dots, lines, unevenness and the like. Since line defects are caused by scratches or dirt in drums, rollers, or the like provided in printing devices such as printers or reading devices such as scanners and often occur continuously, the line defects are thus strongly required to be detected.
For example, Japanese Unexamined Patent Application Publication No. 2014-71045 discloses a technique for detecting such line defects by performing filtering processing and the like.
By the way, since line defects are defects occurring over large areas, even low density line defects are required to be detected.
However, when detecting low density line defects by the conventional technique as described above, strong noise occurring during a printing or reading process cannot be distinguished from low density line defects, and therefore the noise may be wrongly detected as line defects.